L.B. White AW250, Owner'S Manual And Instructions

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The high limit switch should be tested a minimum of once
per year when the heater is given a thorough cleaning.
1. Remove the high limit switch from the heat chamber.
2. Holding the switch by one of its mounting legs or
electrical terminals, apply a small flame only to the
sensing surface on the back of the switch. Be careful
not to melt the plastic housing of the switch when
conducting this test.
3. Within a minute, you should hear a pop coming from
the switch, which indicates the contacts of the switch
have opened.
4. Allow the switch cool down for about a minute before
firmly pressing the red reset button on the switch.
5. Check for electrical continuity across the switch
terminals to make sure the contacts have closed.
6. Reinstall the switch back into the heater. Reconnect
the heater to its electrical supply. Start the heater
and check for proper operation.
FIG. 14
TESTING THE MANUAL RESET HIGH LIMIT SWITCH
WARNING
Fire Hazard
■
Do not operate the appliance with the high limit switch
bypassed.
■
Operating the heater bypassed high limit switch may
lead to overheating, possibly resulting in a fire, with
subsequent damage to the heater, building damage, or
loss of livestock.
RESET BUTTON
SENSING
SURFACE
TERMINAL
FLAME
MOUNTING
LEG
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